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CONNECTICUT 

AGRICULTURAL  EXPERIMEHT  STATION 

NE\V    HAVEN,    CONN. 


BULLETIN    178,  SEPTEMBER,  1913. 


THE  CHESTNUT  BARK  DISEASE 


CONTENTS.  Page 

Cause  of  Disease 6 

Description  of  Disease 6 

Remedies  Tried 7 

Dissemination  of  Spores 8 

Progress  of  Disease 9 

Distribution  in  Connecticut 9 

Distribution  in  the  United  States 1 1 

Relation  to  Host  Conditions I2 

Present  Situation  and  Future  Prospects  in  Connecticut 12 

Work  Done  in  Connecticut 13 

Work  Done  by  Other  States 14 

Historical 15 

Range  and  Conditions  of  Growth 15 

Character  of  Wood  and  Utilization 16 

Mill  Practice 17 

Recommendations 18 

The  Bulletins  of  this  Station  are  mailed  free  to  citizens  of  Con- 
necticut who  apply  for  them,  and  to  others  as  far  as  the  editions 
permit. 


H-3 
10, 1  ?-'^ 


COHNECTICDT  AGRICULTDML  EXPERIMENT  STATION, 


OIFIFIOEIRS    J^IsTID    ST-A-IFJF. 


BOARD  OF  CONTROL. 

His  Excellency,   Simeon  E.  Baldwin,  ex  officio.  President. 

Prof.  H.  W.  Conn,  Vice  President Middletown 

George  A.  Hopson,  Secretary Wallingford 

E.  H.  Jenkins,  Director  and'  Treasurer New  Haven 

J  osEp?i  W.  Alsop Avon 

Wilson  H.  Lee Orange 

Frank  H.  Stadtmueller , Elmwood 

James  H.  Webb Hamden 


Administration. 


Chemistry. 

Analytical  Laboratory. 


station  staff. 

E.  H.  Jenkins,  Ph.D.,  Director  and  Treasurer. 

Miss  V.  E.  Cole,  Librarian  and  Stenographer. 

Miss  L.  M.  Brautlecht,  Bookkeeper  and  Stenographer . 

William  Veitch,  In  Charge  of  Buildings  and  Groujtds. 

John  Phillips  Street,  M.S.,  Chetnist  in  Charge. 
E.  Monroe  Bailey,  Ph.D.,    C.  B.  Morison,  B.S., 
C.  E.  Shepard,  G.  L.  Davis,  Assistants. 
Hugo  Lange,  Laboratory  Helper. 
V.  L.  Churchill,  Sampling  Agent. 
Miss  E.   B.  Whittlesey,  Stenographer. 


Proteid  Research. 


T.  B.  Osborne,  Ph.D.,  Chemist  in  Charge. 
Miss  E.  L.  Ferry,  M.S.,  Assistant. 


Botany. 


G.  P.  Clinton,  S.D.,  Botanist. 

E.  M.  Stoddard,  B.S.,  Assistant. 

Miss  M.  H.  Jagger,  Seed  Analyst. 

Miss  E.  B.  Whittlesey,  Herbarium  Assistant. 


Entomology. 


W.  E.  Brittom,  Ph.D.,  Entomologist ;  State  Entomologist. 
B.   H.    Walden,  B.Agr.,  First  Assistant,    Q.  S.  Lowry, 
B.S.,  I.  W.  Davis,  B  S.,  Assistants. 
Miss  F.  M.  Valentine,  Stenographer. 


Forestry. 


Walter  O.  Filley,  Forester;  also  State 

Forester  and  State  Forest  Fire  Warden. 
A.  E.  Moss,  M.F.,  Assistant  Statical  Forester. 
Miss  E.  L.  Avery,  Stenographer. 


•    Plant  Breeding. 


H.  K.  Hayes,  M.S.,  Plant  Breeder. 
C.  D.  HuBBELL,  Assistant. 


GENERAL    DESTRUCTION    OF    CHESTNUT    BY    BLIGHT. 


THE  CHESTNUT  BARK  DISEASE. 

Endothia  gyrosa  var.  parasitica  (Murr.)  Clint. 

By  E.  M.  Stoddard,  Asst.  Botanist, 
and  A.  E.  Moss,  Asst.  Forester. 

To  the  owner  of  chestnut  woodland  the  vital  questions  are; 
What  is  killing  the  chestnuts?  and,  What  are  the  prospects  of 
maintainino-  the  chestnut  as  a  forest  tree  ? 


FIG.     I.       TREES    KILLED    BY    CHESTNUT    BLIGHT. 


It  is  the  purpose  of  this  bulletin  to  answer  the  first  question 
and  to  give  such  other  information  that  the  reader  may  have  a 
clearer  understanding  of  the  problem  and  judge  for  himself  what 


6         CONNECTICUT    EXPERIMENT  §TATION,    BULLETIN    NO.    I78. 

is  the  best  course  to  pursue  under  the  particular  conditions  in 
which  his  woodlot  is  situated. 

CAUSE   OF   DISEASE. 

First  of  all,  let  it  be  clearly  understood  that  the  chestnut  blight 
is  caused  by  a  fungus  and  not  by  an  insect j  as  is  often  erroneously 
supposed.  The  fact  that  insects  of  various  kinds  are  found  in 
the  dead  bark  of  an  affected  tree  has  often  led  to  the  conclusion 
that  the  trouble  is  of  insect  origin,  but  such  is  not  the  case  and 
insects  have  no  part  in  causing  chestnut  blight. 


DESCRIPTION. 

The  chestnut  disease  is  caused  by  the  fungus  technically  known 
as  Endothia  gyrosa  var.  parasitica.    This  fungous  parasite  pene- 


FIG.    II.       BLIGHT    STARTED    THROUGH    INSECT    INJURY   (a),    AND    PRUNED    BRANCH    (b); 
C.       MATURE    FRUITING    PUSTULES    ON    SMOOTH    BARK. 


CHESTNUT    BARK   DISEASE.  7 

trates  the  bark  to  the  wood  of  the  chestnut  tree,  killing  the 
invaded  tissues,  but  does  not  enter  into  the  wood  to  any  appre- 
ciable extent  nor  does  it  affect  directly  any  part  of  the  tree 
other  than  that  with  which  it  comes  in  contact.  The  tree  or 
branch  is  killed  only  when  the  disease  goes  completely  around 
it,  thus  girdling-  it  and  stopping  the  flow  of  sap  to  the  parts 
above  the  infected  area. 

The  mycelium  or  vegetative  part  of  the  fungous  plant  grows, 
as  has  been  stated  before,  in  and  beneath  the  bark  and  the  spores 
are  borne  in  characteristic  red-brown  or  orange-colored  pus- 
tules. These  are  seen  dotting  the  surface  of  the  cankers  on 
smooth  bark  and  thickly  clustered  in  the  crevices  of  rough  bark. 
The  spores  are  the  bodies  by  which  the  organism  perpetuates 
itself  and  are  borne  on  the  fruiting  pustules  in  countless  num- 
bers. There  are  two  forms  of  these  spores,  one  of  which  is 
borne  in  the  summer  and  the  other  in  late  fall  and  winter,  both 
being  capable  of  infecting  chestnut  trees  under  the  proper  con- 
dition. So  small  are  the  summer  spores  that  8,000  of  them  placed 
end  to  end  equal  an  inch  in  length.  The  chestnut  blight  fungus 
does  not  so  far  as  known  injure  any  other  kind  of  tree  nor  does 
it  usually  attack  a  tree  unless  the  bark  has  been  injured  or  the 
tree  is  in  a  weakened  condition.  It  has,  however,  been  found  to 
a  very  limited  extent  on  a  few  oaks,  but  never  doing  any  appre- 
ciable injury. 


REMEDIES    TRIED. 

At  present  there  are  no  sure  remedies  known  for  this  dis- 
ease, because  the  fungus  grows  wholly  within  the  tree,  only 
its  fruiting  pustules  appearing  on  the  surface,  thus  making  it 
very  difficult  to  control  the  disease  by  spraying  even  if  it  were 
practicable  to  do  spraying  in  a  chestnut  forest.  Other  methods 
of  control  have  also  proved  unsuccessful. 

Spraying.  It  has  been  claimed  that  spraying  with  Bordeaux 
mixture  will  prevent  trees  from  becoming  infected,  which  it 
doubtless  would  if  the  tree  had  no  wounds  in  the  bark  and 
could  be  covered  completely  with  the  mixture  at  all  seasons  of 
the  year.     But  this   is   nearly   impossible   and   surely   impracti- 


8         CONNECTICUT    EXPERIMENT    STATION,    BULLETIN    NO.    I78. 

cable  except  perhaps  on  single  trees  used  for  ornamental  pur- 
poses. 

Medication.  Injecting  various  substances  into  the  tree  has 
been  tried  but  with  no  success,  as  any  substance  sufficiently 
poisonous  to  kill  the  blight  is  injurious  to  the  tree,  and  further- 
more it  is  difficult  to  make  a  tree  absorb  any  very  great  amount 
of  material  injected  into  it. 

Cutting  Infected  Trees.  The  removing  of  all  infected  trees 
has  been  tried  but  as  with  the  other  remedies  its  success  has 
been  only  indifferent  at  the  best,  as  it  is  hard  to  find  all  infected 
trees  when  scouting-  for  the  disease,  and  the  few  not  found  are 
sources  of  new  infections.  The  expense  and  trouble  of  destroy- 
ing- infected  portions  of  the  tree  after  cutting  makes  this  method 
of  control  out  of  the  question  for  treating  chestnut  woodland. 

Thus  at  present  we  are  without  any  effective  method  of  com- 
bating this  trouble  in  the  forest  and  at  best  are  only  partly 
successful  with  single  specimens  in  a  yard  or  park. 


DISSEMINATION    OF   SPORES. 

There  are  several  ways  in  which  the  blight  may  be  spread,  but 
from  our  own  observations  it  would  seem  that  the  wind  and 
possibly  birds,  especially  those  which  hunt  for  larvae  of  insects 
in  the  bark,  are  chiefly  responsible.  It  can  be  readily  seen  that 
when  an  affected  tree  is  producing  countless  millions  of  such 
minute  spores  the  wind  will  easily  blow  them  to  a  considerable 
distance.  This  is  especially  true  of  the  winter  spores,  which  are 
forcibly  ejected  from  the  sacs  in  which  they  are  borne.  These 
spores  lodging  in  a  wound  in  the  bark  of  a  chestnut  tree  or 
being  washed  there  by  the  rain  would  start  a  new  infection  of 
the  disease.  As  the  summer  spores  are  produced  in  sticky 
masses,  birds  may  pick  them  up  on  their  beaks  and  feet  and 
thus  carry  them  to  new  localities.  Other  ways  of  dissemination 
are  insects  and  transportation  of  diseased  chestnut  wood  from 
one  place  to  another.  The  fungus  often  produces  spores  for  one 
or  two  years  on  cut  wood  especially  when  the  bark  has  been 
left,   so  that   diseased  wood   can  be   a   source   of   infection   for 


CHESTNUT    BARK    DISEASE.  9 

some  little  time.     Rains  are  very  effective  in  washing"  spores  to 
various  parts  of  the  tree  below  the  infected  portion. 

PROGRESS    OF   DISEASE. 

While  we  have  not  much  definite  data  at  hand  to  show  just 
how  fast  the  disease  progresses  after  attacking  a  large  tree,  we 
have  found  by  inoculating  small  seedlings  and  sprouts  that 
these' may  be  entirely  girdled  in  one  season,  and  from  general 
observations  on  marked  trees  at  Stamford  and  Middlebury  it 
takes  at  least  two  years  to  kill  the  tree  and  probably  three  or 
four.     Of   course   how   long-  it  takes   the  blight  to   kill   a  tree 


FIG.    III.       SPROUT    WITH    DEAD    BARK    AROUND    INOCULATION    POINT, 

depends  on  where  the  tree  is  attacked.  If  it  is  attacked  on  the 
small  branches  these  will  be  killed  but  the  rest  of  the  tree  will 
remain  healthy  and  in  a  growing  condition  for  a  considerable 
time.  On  the  other  hand  if  the  infection  is  on  the  main  trunk 
this  will  be  girdled  and  the  entire  tree  killed  in  a  much  shorter 
time.  Certain  weather  conditions  also  apparently  affect  the  rate 
of  development  of  the  fungus. 

DISTRIBUTION    IN    CONNECTICUT. 

At  the  present  time  the  chestnut  blight  is  distributed  entirely 
over  Connecticut.  The  accompanying  maps  show  its  spread  from 
1908  to  1912  and  also  show  approximately  the  varying  degrees 
of  damage  done  in  various  parts  of  the  state.  The  trouble 
is  more  serious  in  the  southwestern  part  of  the  state  and  west  of 
the  Connecticut  River.  This  is  probably  due  to  the  fact  that 
there   is  more  chestnut  in   the  western   half.     It   was    reported 


DISEASE    NOT  REPDRTED 
DISEASE   NOT  BAD 
DISEASE    BAD 


FIG.    IV.       KNOWN    DISTRIBUTION    OF    CHESTNUT    BLIGHT    IN    IC 


DISEASE  NDT  BAD 
DISEASE  BAD 
DISEASE   VERY  BAD 


FIG,    V.       KNOWN    DISTRIBUTION    OF    CHESTNUT    BLIGHT   IN    I9I2. 

DISTRIBUTION   OF  CHESTNUT  BLIGHT  IN  CONNECTICUT. 


CHESTNUT    BARK   DISEASE.  II 

first  in  the  southwestern  towns  of  the  state  but  recent  studies  of 
the  disease  prove  that  it  was  present  to  a  greater  or  less  degree 
in  scattered  locaHties  throughout  the  state  as  early  as  in  these 
reported  towns. 

DISTRIBUTION    IN    THE    UNITED   STATES. 

Chestnut  blight  is  present  in  Massachusetts  along  and  west  of 
the  Connecticut  River,  in  Rhode  Island  it  is  scattered  and  seri- 


FIG.  VI.   A-B.   CANKKRS  ON  SMOOTH  (a)  AND  ROUGH  (k)  BARKED  TREES. 


ous  in  certain  localities,  and  it  has  also  been  reported  from  Ver- 
mont and  New  Hampshire.  In  New  York  it  is  progressing 
north  along  the  Hudson  River  and  is  present  in  western 
Long  Island.  In  New  Jersey  the  chestnut  has  suffered  over  the 
entire  state  and  in  Pennsylvania  the  trouble  is  serious  in  the 
eastern  and  bad  in  the  southeastern  part.  The  disease  occurs  gen- 
erally in  Delaware,  while  Maryland,  Virginia  and  West  Virginia 
have  it  scatteringly,  the  points  of  infection  being  iew  and  incon- 
spicuous in  the  latter  state.     Thus  we  see  that  the   disease  is 


12       CONNECTICUT    EXPERIMENT    STATION,    BULLETIN    NO.    I78. 

spread  in  varying  degrees  of  seriousness  over  nearly  the  entire 
northern  territory  where  chestnut  grows. 


RELATION    TO    HOST    CONDITIONS. 

From  our  own  observation  and  from  the  opinions  of  wood- 
land owners  who  have  watched  the  spread  of  the  disease  it  would 
seem  that  the  dry  seasons,  which  are  unfavorable  for  the  growth 
of  the  chestnut,  have  been  an  important  factor  in  the  spread  of 
the  disease.  It  has  been  found  that  chestnut  growing-  on  dry 
hill-tops  is  generally  more  seriously  affected  with  the  blight 
than  that  in  lower  land  where  there  is  more  moisture.  Chest- 
nut growing  on  dry  hillsides  has  been  evidently  killed  entirely  by 
dry  conditions,  as  no  blight  could  be  found ,  on  it.  Chestnut 
injured  by  fire  or  in  other  ways  is  invariably  more  quickly 
attacked  by  this  disease  and  often  it  is  the  trunks  of  these  trees 
which  are  infected,  thus  causing-  the  death  of  the  tree  much 
quicker  than  if  the  twigs  and  small  branches  were  attacked. 

Instead  of  the  chestnut  bark  disease  being  an  introduced  dis- 
ease as  is  thought  by  some,  it  seems  more  probable  that  it  was 
present  in  this  country,  growing  inconspicuously  on  dead  and 
dying  trees,  and  that  after  the  chestnut  was  weakened  by  a 
succession  of  dry  seasons  it  became  an  active  parasite  and 
attacked  and  killed  living  trees. 


PRESENT    SITUATION    AND    FUTURE    PROSPECTS    IN    CONNECTICUT. 

The  present  situation  in  Connecticut  is  that  the  disease  is  still 
spreading  and  unless  its  progress  is  checked  by  some  natural 
causes  the  future  prospects  are  not  bright  for  chestnut  in  this 
state.  However,  instances  have  been  noted  where  trees  were 
overcoming  the  disease  and  blight  cankers  which  had  attained 
a  diameter  of  eighteen  inches  were  healing  over,  this  healing 
process  having  been  begun  in  191 1..  This  condition  is  not  gen- 
eral, but  if  it  is  possible  for  some  trees  which  have  had  favorable 
growing  conditions  to  overcome  the  disease  we  may  expect  that 
if  the  seasons  are  such  that  the  trees  are  able  to  make  a  more 
vigorous  growth  the  disease  will  decrease  in  virulence  consider- 
ably. Of  course,  predictions  as  to  the  final  outcome  are  at  best 
rather  uncertain  and  evidence  at  hand  furnishes  arguments  for 


CHESTNUT    BARK    DISEASE.  1 3 

both  the  optimisL  and  the  pessimist,  but  until  the  chestnut  is 
nearer  extinction  than  at  present,  a  prediction  of  ultimate  destruc- 
tion does  not  seem  warranted. 


WORK   DONE    IN    CONNECTICUT. 

The  work  done  on  the  chestnut  blight  in  Connecticut  by  the 
Experiment  Station  consists  of  a  survey  of  the  state  to  determine 
the  extent  and  seriousness  of  the  disease,  and  of  a  thorough 
inspection  of  a  tract  on  the  state  forest  in  Portland  for  the  pur- 
pose of  locating  and  cutting  out  diseased  trees  and  also  a  plot 
Avhere  affected  trees  were  located,  counted  but  not  cut  out. 
Besides  this  a  large  amount  of  laboratory  work  has  been  done 
to  determine  various  points  of  scientific  interest  in  regard  to  the 
life  history  and  cultural  characteristics  of  the  blight  fungus. 

The  survey  of  the  state  was  made  by  members  of  the  Botanical 
and  Forestry  Departments  visiting  and  locating  the  disease  in 
all  towns  from  which  specimens  had  not  already  been  received. 
In  this  survey  no  attempt  was  made  to  locate  definitely  all  the 
points  of  infection  in  every  town,  but  each  town  was  inspected 
in  a  very  general  way  to  locate  the  disease  and  get  an  approxi- 
mate idea  of  the  amount  of  chestnut. 

The  work  in  the  Portland  forest  consists  of  a  thorough  inspec- 
tion of  a  definite  tract  in  which  all  infected  trees  are  located,  cut 
out,  the  brush  burned  and  the  infected  timber  removed  and 
peeled.  Such  as  is  not  large  enough  for  timber  is  burned  for 
charcoal  nearby.  As  a  check  on  the  results  obtained  on.  this 
tract  an  adjacent  tract  is  inspected,  the  trees  counted  and  not  cut 
out,  thus  showing  whether  the  cutting  out  has  any  control  on  the 
disease.  This  has  been  done  for  two  years  and,  while  the  results 
have  so  far  been  negative,  this  experiment  must  be  carried  on  for 
a  series  of  years  to  arrive  at  definite  conclusions.  Besides  this 
inspection  a  small  amount  of  work  has  been  done  in  the  way  of 
peeling  or  burning  the  infected  stumps  to  determine  the  effect 
of  such  treatment  on  the  sprouting  of  the  stumps  and  on  the 
destruction  of  the  disease.  At  this  writing  it  is  too  early  to  say 
what  the  results  of  this  experiment  will  be.  Judging  from  the 
time  taken  to  do  a  small  amount  of  such  work  it  would  prove 
too  expensive  for  the  owner  of  timber  land  to  undertake  cutting 
diseased  trees  and  burning  the  stumps. 


14      CONNECTICUT    EXPERIMENT    STATION,    BULLETIN    NO.    I78. 
WORK   DONE    BY   OTHER    STATES. 

The  work  of  studying  and  combating  chestnut  bhght  has  been 
taken  up  by  the  various  states  in  various  ways  and  on  a  larger 
or  smaller  scale  according  to  the  views  of  the  investigators  and 


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FIG.    VII.       SMALL    BRANCHES    ON    OPEN    GROWN    TREE    KILLED    BY    BLIGHT. 


to  the  amounts  of  money  appropriated  for  the  work.  Massachu- 
setts has  done  some  work  in  locating  the  diseased  areas,  but  noth- 
ing in  the  way  of  control  measures,  the  same  course  being  fol- 
lowed by  Rhode  Island.  Pennsylvania  has  expended  $275,000  on 
the  study  and  work  of  combating  the  bHght.  Spraying",  cut- 
ting out  infected  trees,  medication  and  tree  surgery  were  tried. 


CHESTNUT    BARK   DISEASE.  IS 

and  while  many  experiments  of  interest  have  been  performed  no 
very  definite  progress,  in  our  opinion,  has  been  made  in  discover- 
ing successful  and  practical  measures  of  control. 

Maryland,  Virginia  and  West  Virginia  are  expending  small 
sums  on  locating  points  of  infection  with  an  idea  of  possibly 
removing  the  scattered  areas  of  infection  at  a  later  date  if  the 
success  of  such  treatment  shall  seem  to  warrant  it.  The  chest- 
nut in  New  Jersey  and  Delaware  has  been  so  nearly  destroyed 
that  little  work  of  any  kind  has  been  undertaken. 

HISTORICAL    CONSIDERATION. 

The  chestnut  blight  was  first  noticed  in  the  New  York  Zoologi- 
cal Park  by  H.  W.  Merkel  in  the  summer  of  1904.  In  1905  it 
was  so  serious  that  measures  were  taken  to  control  it,  and  the 
first  description  of  the  trouble  was  published  in  the  report  of 
the  New  York  Zoological  Society  for  that  year.  From  a  botani- 
cal standpoint  the  first  work  was  done  by  W.  A.  Murrill  of  the 
New  York  Botanical  Garden  in  1906.  Shortly  after  Murrill's 
work  the  study  of  the  blight  was  taken  up  by  Clinton  of  this 
Station  and  by  Metcalf  and  Collins  of  the  United  States  Depart- 
ment of  Agriculture.  Since  then  many  investigators  have  become 
interested  in  the  study  of  this  disease  and  the  opinions  and  dis- 
coveries have  been  nearly  as  numerous  as  the  investigators. 

RANGE   AND    CONDITIONS    OF    GROWTH. 

Chestnut  ranges  from  southern  New  Hampshire  south  to 
Georgia  and  Alabama.  Connecticut  is  near  the  northern  limit 
of  its  range,  which  accounts  for  the  decrease  in  per  cent,  of 
this  species  toward  the  northern  part  of  the  state  and  on  the 
cool  northern  slopes. 

It  occurs  nearly  pure  on  medium  to  deep  well-drained  sites, 
but  on  the  drier  ridges  and  in  the  swamps  it  is  crowded  out  of 
the  stand  by  species  better  adapted  to  the  conditions.  This 
tree  requires  direct  light  and  forms  a  wide  spreading  tree  in 
the  open,  while  in  the  forest  the  demand  for  light  causes 
increased  height  growth,  forming  a  clear  full-boled  tree.  Chest- 
nut sprouts  very  abundantly,  even  when  the  tree  cut  is  100 
years  or  more  in  age.  The  nuts  are  largely  eaten,  but  a  few 
are  scattered  by  the  birds  and  animals  which  accounts  for  the 
numerous   seedling  trees   to  be   seen  in  abandoned  fields.     The 


l6       CONNECTICUT    EXPERIMENT    STATION,    BULLETIN    NO.    I78. 

Sprout  tree  grows  much  more  rapidly  in  youth  but  the  seed  tree 
will  often  overtake  and  pass  it  in  forty-five  or  fifty  years. 

Chestnut  forms  the  larger  part  of  the  stand  in  the  southern 
counties  of  the  state  but  decreases  in  the  northern  portion,  where 
white  pine  is  more  abundant.  East  of  the  Connecticut  River 
it  does  not  form  as  large  a  percentage  of  the  stand  as  in  the 


FIG.    VIII.       PURE    STAND    OF    CHESTNUT. 


western  part  of  the  state.     It  usually  occurs  in  pure  stands  or 
mixed  with  oak,  tulip,  and  other  hardwoods. 


CHARACTER    OF    WOOD    AND    UTILIZATION. 

Its  wood  is  durable  in  contact  with  the  soil  and  has  been 
largely  used  in  the  form  of  posts,  ties,  and  other  products  which 
are  exposed  to  the  weather.  The  stands  in  the  northern  portion 
of  the  state  have  been  coaled  a  number  of  times  to  furnish  char- 
coal for  the  iron  mines  which  have  been  in  operation  there  since 
colonial  days.  The  wood  is  soft  and  easy  to  cut,  and  when  dry 
burns  with  a  steady  heat  leaving  little  ash,  which  fact  has 
resulted  in  the  use  of  this  species  to  the  almost  total  exclusion 


CHESTNUT    BARK   DISEASE.  1 7 

of  the  hard  woods  in  the  brass  industry.  The  brickyards  and 
the  Hme  kilns  also  use  it  when  it  can  be  obtained.  These 
numerous  uses  for  the  smaller  products,  such  as  cordwood,  have 
resulted  in  large  areas  of  sprout  forests  under  30  years  of 
age,  in  which  the  percentage  of  chestnut  has  been  on  the  increase, 
due  to  the  great  vigor  with  which  the  stumps  sprout.  In  those 
sections  of  the  state  where  the  market  for  cordwood  is  not  as 
good,  the  stands  are  usually  left  until  pole  or  tie  size.  Here  the 
percentage  of  seedling  trees  is  slightly  greater,  due  to  the 
increased  seed  production  of  the  more  mature  trees.  These 
stands,  as  a  whole,  are  mixed  with  a  greater  variety  of  species 
and  are  in  a  better  condition  to  withstand  the  spread  of  the 
chestnut  blig"ht,  as  there  are  in  many  cases  enough  trees  of  other 
species  to  continue  the  stand  even  if  the  chestnut  is  entirely 
removed.  There  are  very  few  stands  in  the  state  in  which  the 
trees  are  of  a  size  to  make  lumber.  This  is  largely  due  to 
the  ready  market  for  ties  and  poles,  but  it  is  also  due  to  the 
fact  that  in  a  sprout  stand  the  trees  begin  to  deteriorate  after 
it  reaches  the  age  of  fifty  to  sixty  years. 

Native  chestnut  is  the  wood  most  used  in  this  section  for  ties 
and  poles.  Chestnut  and  red  cedar  are  most  commonly  used 
for  posts.  Chestnut  is  used  for  timbers  in  the  construction  of 
a  large  number  of  buildings,  especially  on  the  farm  where  the 
owner  has  his  own  wood  lot.  When  the  tree  is  large  enough 
to  saw,  the  planks  are  commonly  used  in  the  wooden  bridges  to 
be  found  throughout  the  state.  The  boards  are  used  as  rough 
siding  and  to  a  limited  extent  in  the  manufacture  of  boxes,  but 
this  use  is  limited  by  the  weight  of  the  lumber.  As  an  interior 
finish,  this  wood  is  coming  into  favor,  but  up  to  the  present  time 
the  southern  lumber  is  preferred  because  of  better  milling  and 
closer  grading.  Chestnut  is  used  in  furniture  as  the  core  for 
veneering. 

MILL    PRACTICE. 

The  chestnut  of  this  state  is  milled  by  small  portable  outfits 
which  have  a  daily  capacity  of  five  to  fifteen  thousand  feet  per 
•  day.  The  timber  holdings  are  small  and  a  mill  has  to  make 
frequent  moves  which  tends  to  make  the  owner  careless  in 
setting  up,  with  the  result  that  there  is  a  tendency  to  produce 
lumber  of  varying  thickness.     The  mills  have  circular,  inserted 


l8      CONNECTICUT    EXPERIMENT    STATION,    BULLETIN    NO.    I78. 

tooth  saws  which  cut  out  a  9-32  inch  kerf,  which  means  a  loss 
of  one  board  in  four.  This  is  probably  unavoidable  as  the 
stands  of  timber  are  so  small  that  any  other  form  of  mill  is 
out  of  the  question,  but  the  unnecessary  loss  due  to  the  saw 
not  lining  up  or  the  teeth  not  being-  in  good  shape  is  avoidable. 
Where  the  stand  is  being  cut  for  ties  the  felling  crews  cut  the 
logs  into  tie  lengths,  and  the  sawyer  does  not  save  the  boards 
that  the  cut  may  contain  above  the  tie  contents,  as  there  is  little 
demand  for  eight-foot  boards.  If  the  logs  were  cut  in  two 
tie  lengths,  this  question  of  the  short  board  would  be  avoided 
and  a  merchantable  product  obtained  in  place  of  a  thick  slab. 

The  sale  of  a  stand  by  the  thousand  feet  is  undesirable  since 
there  is  then  a  tendency  on  the  part  of  the  operator  to  cut  as 
rapidly  as  possible,  and  not  to  get  the  maximum  amount  out 
of  each  log.  There  is  a  lack  of  appreciation  of  the  loss  from 
the  cutting  of  high  stumps  and  leaving  merchantable  material 
in  the  tops.  If  the  stump  is  six  inches  too  high,  the  loss  in  the 
average  tree  is  from  one  to  two  per  cent,  and  it  is  the  best  timber 
in  the  tree  which  is  wasted. 

RECOMMENDATIONS. 

Cutting  a  stand  of  chestnut  simply  because  there  are  a  few 
diseased  trees  scattered  through  it  is  to  be  avoided  if  possible. 
The  stand  should  be  watched  and  when  the  loss  from  the  disease 
is  greater  than  the  increase  by  growth  the  stand  should  be  cut. 
The  value  of  the  timber  is  steadily  increasing  so  long  as  it  is 
growing  thriftily,  and  it  is  good  policy  to  hold  a  stand  as 
long  as  possible,  to  get  the  greatest  possible  growth  and  this 
increase  in  value.  A  tree  killed  by  the  blight  is  still  merchant- 
able, as  the  timber  is  not  affected  so  far  as  can  be  determined 
by  test. 

The  owner  of  a  timber  lot  should  cut  out  the  diseased  trees, 
not  so  much  to  prevent  the  spread  of  the  infection  as  to  save 
the  material  already  grown.  In  cutting  a  stand  it  is  advisable 
to  leave  species  other  than  chestnut  so  that  there  may  be  some 
reproduction  by  seed  to  take  the  place  of  the  chestnut  if  it  does 
not  recover  sufficiently  to  sprout. 

In  a  pure  chestnut  stand  where  the  infection  is  bad,  clearing 
of  brush  and  planting  with  pine  is  the  best  method  for  keeping 
the  area  in  forest. 


CHESTNUT    BARK    DISEASE.  I9 


SUMMARY. 

1.  The  chestnut  blight  is  caused  by  the  parasitic  fungus  Endothia 
gyrosa  var.  parasitica  and  not  by  an  insect. 

2.  The  chestnut  bark  disease  is  slowly  and  surely  killing  the  chest- 
nut in  Connecticut,  and  will  continue  to  do  so  unless  stopped  by  natu- 
ral causes  or  some  effective  remedy  can  be  found. 

3.  All  methods  of  control  that  have  been  tried  have  proven  only 
partially  successful  and  are  not  practical  for  use  in  woodland. 

4.  It  is  believed  that  dry  weather  conditions  have  weakened  the  tree 
and  enabled  a  native  fungus  to  become  an  active  parasite  and  that  the 
disease  has  not  been  introduced  from  a  foreign  country. 

5.  If  individual  infected  trees  are  cut  and  the  bark  and  brush  burned 
on  the  stumps,  the  spread  of  the  disease  may  be  checked,  but  experi- 
ments show  that  in  most  cases  the  surrounding  trees  are  already 
infected,  and  the  disease  is  only  temporarily  checked. 

6.  The  presence  of  the  disease  in  the  stand  in  itself  is  not  sufficient 
reason  for  cutting.  Unless  the  trees  are  mature  and  the  market  con- 
dition is  good,  it  is  better  to  give  the  uninfected  trees  a  chance  to 
get  all  the  growth  possible,  especially  where  the  presence  of  the 
blight  has  only  just  become  apparent. 

For  a  more  detailed  report  on  this  subject  the  reader  is  referred 
to  the  Report  of  the  Botanist,  Connecticut  Agricultural  Experiment 
Station,  1911-1912. 


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